"Graphic design occupies the intersection of the science of communication and the art of aesthetics. In its most abstract sense, graphic design emphasizes visual communication using a range of elements and different media to promote a specific message.

Graphic Design Principles
Because graphic design—sometimes also called communication design—enables more effective storytelling, designers work from a standardized toolkit of options that have been shaped by peer-reviewed psychological studies of human behavior. The various techniques that designers employ, like using specific color palettes to elicit predictable emotional responses, are part of the science of design. 

Designers consider elements like:

Type — Typography (the selection and sizing of specific typefaces) can convey meaning. For example, a heavy sans-serif font conveys an authority that a thin-stroke scripted font does not.
Shape — Shapes speak to audiences in different ways. Ovals, for example, tend to be welcoming (which is why so many ""open"" signs are surrounded by them), whereas square shapes present a tidier appearance. Even on the page itself, the ordering of graphic elements into predictable or random patterns contributes to the overall communication effect.
Color — Colors and their juxtaposition directly influence the audience's emotional engagement with a designed piece.
Texture — Ink-on-paper gets the job done, but adding non-standard elements like fabric, foil or embossing offer a tactile experience that influences and extends the audience's perception of the design as a whole.
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